The objective of this protocol is to perform a single dose bioavailability study of Neosten 25 mg, and compare it with that of plain sodium fluoride 10 mg. It will test the hypothesis that at the same bioequivalent dose, plain NaF would be more rapidly absorbed and would cause a higher serum fluoride peak, than Neosten. Thus, it is expected that plain NaF 10 mg, compared to Neosten 25 mg, would yield a higher peak werum fluoride concentration, shorter time to reach peak and half time of decline, but an equivalent change in area under the curve.